I need help to figure out the formula / equation or at least the growth rate based on this table. All I can see is that the base stat is 12 as STAT2 = 2 x base and STAT3 = 5 x base.
I tried to figure this out by creating an MS Excel spreadsheet and experimenting with different formulas until I found one which works.
A formula which approximates the values in that table very closely seems to be
a + b * (level / 10)² with the following values for a and b:
a b STAT1 12 10 STAT2 24 20 STAT3 60 50
It is not an exact fit. the results for level 100 are 1012, 2024 and 5060 respectively. But this is likely close enough for your purpose.
If the table comes from a different game and you want to clone it, then you shouldn't try to copy them too closely anyway in order to avoid copyright problems.
If this is a table from your own game and you are trying to reverse-engineer it because the knowledge how to create it was lost, then a 0.06% deviation is unlikely to turn your game balance upside down. (but on the other hand, I know absolutely nothing about your game mechanics, so I can't be completely certain about that)
The best fit I found was via cubic fit (least squares). the last two stats were almost spot on entirely, and the first one was only about 99.98% fit or something which yielded the following results:
// let x represent the level, and y represent the corresponding stat's output // Stat1: y = -3.99983×10^-6 x^3 + 0.100512 x^2 - 0.00664512 x + 11.5483 // Stat2: y = -1.57334×10^-8 x^3 + 0.200103 x^2 + 0.00463321 x + 23.5259 // Stat3: y = 0.0000107514 x^3 + 0.498893 x^2 + 0.0373237 x + 59.5811
if you round the resulting y quantity to its nearest integer, you will find the results extremely accurate.